Power supply with high and low power operating modes

ABSTRACT

A method for controlling a battery-powered power supply. The method includes generating a first output from a first power supply within the battery-powered power supply. The first output is coupled to an output bus. The method further includes monitoring a voltage of the output bus, and determining, using a controller of the battery-powered power supply, whether the voltage of the output bus is less than a first predetermined level. The method further includes deactivating the first power supply in response to determining that the voltage of the output bus is below the first predetermined level, and generating a second output from a second power supply within the battery-powered power supply. The second output is configured to be coupled to the output bus. The second power supply has a higher output rating than the first power supply.

RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/337,888, filed Jun. 3, 2021, now U.S. Pat. No. 11,539,234, whichclaims the benefit of U.S. Provisional Patent Application No.63/034,715, filed Jun. 4, 2020, the entire content of each of which isincorporated by reference herein.

BACKGROUND

Battery powered power tools and other devices continue to become moreprevalent on jobsites, residential tool sets, and the like.Additionally, other devices such as smartphones, tablet computers,heater wearable gear (e.g. jackets, hats, gloves, etc.) have also becomecommonplace. However, when operating on jobsites, or doing projectsaround a house, there may not be a location to power these devices.Battery powered power supplies may be used to allow for various outputvoltages to be provided to a user using a rechargeable battery pack,such as a power tool battery pack. The power supplies may be configuredto interface with one or more battery types, and can provide one or morevoltage outputs to the user, such as 12 VDC, 5 VDC, and the like.Further, the battery powered power supplies may have one or more outputtypes such as USB, USB-C, etc.

Conventional voltage converters (e.g. switching power supplies) for usein battery powered switching-type power supplies are generally placed onthe load side of a switch or other activation circuit. The switch oractivation circuit is configured to remove power to the voltageconverter when the power supply is not in use, due to the parasiticcurrent draw of the voltage converter. This parasitic current drawconsumes battery power, and can completely drain a battery over time,even when the power supply is not in use. Similarly, other devices mayinclude an activation circuit that allows a user to activate an output,and thereby the voltage converter, for a period of time, such as twohours.

While a switch or activation circuit can eliminate the parasitic draw ofthe voltage converter, a user must remember to switch off the voltageconverter to prevent the battery from being discharged. Similarly, theuse of timers can result in power being shut off to a user prematurely,or to unnecessary discharge of the associated battery.

SUMMARY

Embodiments described herein provide systems and methods for operating abattery powered switching-type power supply to reduce unnecessaryparasitic power draw by a voltage converter without requiring the use ofa switch, activation circuit, or timer.

In one embodiment, a method provides for controlling a battery-poweredpower supply. The methods include generating a first output from a firstpower supply within the battery-powered power supply. The first outputis coupled to an output bus. The methods further include monitoring avoltage of the output bus, and determining, via a controller of thebattery-powered power supply, whether the voltage of the output bus isless than a first predetermined level. The methods further includedeactivating the first power supply in response to determining that thevoltage of the output bus is below the first predetermined level andgenerating a second output from a second power supply within thebattery-powered power supply. The second output is configured to becoupled to the output bus. The second power supply has a higher outputpower rating than the first power supply.

Battery-powered power supplies described herein include a voltageconverter including a first power supply and a second power supply. Thefirst power supply and the second power supply are configured to providean output to a common output bus. The voltage converter is configured toreceive power from a removable battery pack. The battery-powered powersupplies further include a voltage sensor coupled to the output bus andconfigured to sense a voltage on the output bus, a current sensorconfigured to sense a current flowing through the output bus, and acontroller. The controller is configured to monitor a voltage of theoutput bus during an activation period of the first power supply anddetermine whether the voltage of the output bus is less than apredetermined voltage level. The controller is further configured todeactivate the first power supply and activate the second power supplyin response to determining that the voltage is less than thepredetermined voltage level.

In another embodiment, a method provides for controlling abattery-powered power supply. The methods include generating a firstoutput from a first power supply within the battery-powered powersupply. The first output is coupled to an output bus. The methodsfurther include monitoring a power output at the output bus, anddetermining, via a controller of the battery-powered power supply,whether the power output at the output bus is greater than a firstpredetermined level. The methods further include deactivating the firstpower supply in response to determining that the power output at theoutput bus is greater than the first predetermined level and generatinga second output from a second power supply within the battery-poweredpower supply. The second output is configured to be coupled to theoutput bus. The second power supply has a higher output power ratingthan the first power supply.

Before any embodiments are explained in detail, it is to be understoodthat the embodiments are not limited in its application to the detailsof the configuration and arrangement of components set forth in thefollowing description or illustrated in the accompanying drawings. Theembodiments are capable of being practiced or of being carried out invarious ways. Also, it is to be understood that the phraseology andterminology used herein are for the purpose of description and shouldnot be regarded as limiting. The use of “including,” “comprising,” or“having” and variations thereof are meant to encompass the items listedthereafter and equivalents thereof as well as additional items. Unlessspecified or limited otherwise, the terms “mounted,” “connected,”“supported,” and “coupled” and variations thereof are used broadly andencompass both direct and indirect mountings, connections, supports, andcouplings.

In addition, it should be understood that embodiments may includehardware, software, and electronic components or modules that, forpurposes of discussion, may be illustrated and described as if themajority of the components were implemented solely in hardware. However,one of ordinary skill in the art, and based on a reading of thisdetailed description, would recognize that, in at least one embodiment,the electronic-based aspects may be implemented in software (e.g.,stored on non-transitory computer-readable medium) executable by one ormore processing units, such as a microprocessor and/or applicationspecific integrated circuits (“ASICs”). As such, it should be noted thata plurality of hardware and software-based devices, as well as aplurality of different structural components, may be utilized toimplement the embodiments. For example, “servers,” “computing devices,”“controllers,” “processors,” etc., described in the specification caninclude one or more processing units, one or more computer-readablemedium modules, one or more input/output interfaces, and variousconnections (e.g., a system bus) connecting the components.

Relative terminology, such as, for example, “about,” “approximately,”“substantially,” etc., used in connection with a quantity or conditionwould be understood by those of ordinary skill to be inclusive of thestated value and has the meaning dictated by the context (e.g., the termincludes at least the degree of error associated with the measurementaccuracy, tolerances [e.g., manufacturing, assembly, use, etc.]associated with the particular value, etc.). Such terminology shouldalso be considered as disclosing the range defined by the absolutevalues of the two endpoints. For example, the expression “from about 2to about 4” also discloses the range “from 2 to 4”. The relativeterminology may refer to plus or minus a percentage (e.g., 1%, 5%, 10%,or more) of an indicated value.

It should be understood that although certain drawings illustratehardware and software located within particular devices, thesedepictions are for illustrative purposes only. Functionality describedherein as being performed by one component may be performed by multiplecomponents in a distributed manner. Likewise, functionality performed bymultiple components may be consolidated and performed by a singlecomponent. In some embodiments, the illustrated components may becombined or divided into separate software, firmware and/or hardware.For example, instead of being located within and performed by a singleelectronic processor, logic and processing may be distributed amongmultiple electronic processors. Regardless of how they are combined ordivided, hardware and software components may be located on the samecomputing device or may be distributed among different computing devicesconnected by one or more networks or other suitable communication links.Similarly, a component described as performing particular functionalitymay also perform additional functionality not described herein. Forexample, a device or structure that is “configured” in a certain way isconfigured in at least that way but may also be configured in ways thatare not explicitly listed.

Other aspects of the embodiments will become apparent by considerationof the detailed description and accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a battery-powered power supply, according tosome embodiments.

FIG. 2 is a rear view of the battery-powered power supply of FIG. 1 ,according to some embodiments.

FIG. 3 is a perspective view of an alternative battery-powered powersupply, according to some embodiments.

FIG. 4 is a block diagram of a battery-powered power supply, accordingto some embodiments.

FIG. 5 is a flow chart illustrating a process for controlling abattery-powered power supply, according to some embodiments.

DETAILED DESCRIPTION

The below embodiments describe battery-powered power supplies configuredto eliminate, or supplement, the requirement that the user provide aninput to turn the battery powered power supply on and/or off byincorporating a low-power power supply in addition to a high-power powersupply that can be automatically operated based on a sensed load.

FIG. 1 illustrates a side view of a battery-powered power supply 100.The battery-powered power supply 100 is shown as being coupled to abattery pack 102. In some embodiments, the battery pack 102 may be arechargeable power tool battery pack. The battery pack 102 may be an 18VDC battery pack, a 12 VDC battery pack, a 5 VDC battery pack, or othervoltage type battery pack. In some embodiments, the battery pack 102contains one or more battery cells in various series and/or parallelcombinations to provide the desired output voltage. The battery cellsmay be lithium-ion (Li-Ion) battery cells having a chemistry of, forexample, lithium-cobalt (Li—Co), lithium-manganese (Li—Mn), or Li—Mnspinel. In other embodiments, the battery cells may have other suitablelithium or lithium-based chemistries. In still other embodiments, thebattery cells may have other battery chemistries, such as sodium-basedchemistries, Nickel-Cadmium chemistries, lead-acid chemistries, alkalinebattery chemistries, and the like. The battery-powered power supply 100may further include a first output connector 104. The first outputconnector 104 may be a dedicated connection type. However, variousconnection types are contemplated. In some embodiments, the first outputconnector 104 is a 12 VDC output. Voltages of more than 12 VDC or lessthan 12 VDC are also contemplated.

FIG. 2 illustrates a rear view of the battery-powered power supply 100.As shown in FIG. 2 , the battery-powered power supply 100 includes asecond output connector 106. In some embodiments, the second outputconnector 106 is a USB-type connector. In other embodiments, the secondoutput connector 106 may be other types of connector, such as USB-C,Firewire, Micro-USB, Mini-USB, or the like. The second output connector106 may be configured to output a 5 VDC output. However, outputs of morethan 5 VDC or less than 5 VDC are also contemplated. The battery-poweredpower supply 100 is further shown to include a power switch 108, whichis configured to turn the battery-powered power supply 100 ON or OFF.

FIG. 3 illustrates an alternate embodiment of a battery-powered powersupply 300. The battery-powered power supply 300 may be configured tointerface with stick-type battery-pack 302, such as an M12® battery packfrom Milwaukee Tool. Similar to the battery-powered power supply 100described above, the battery-powered power supply 300 may include a userinterface 304 and one or more outputs, similar to those described above.The user interface 304 may be coupled to a controller and configured toactivate an output of the battery-powered power supply 300.

FIG. 4 illustrates a block diagram of a battery-powered power supply400. In some embodiments, the battery-powered power supply 400 issimilar to one of the battery-powered power supplies 100, 300 describedabove. However, other battery-powered power supply types are alsocontemplated. The battery-powered power supply 400 includes terminals402 for connecting to battery terminals 404 of a battery pack 406. Thebattery pack 406 may be a battery pack similar to those described above.In one embodiment, the battery pack 406 is a removable battery pack. Inother embodiments, the battery pack 406 is a non-removable battery pack.The battery-powered power supply 400 further includes a controller 408,a voltage converter 410, a voltage sensor 412, and a current sensor 414.

In some embodiments, the controller 408 is configured to control the oneor more components of the battery-powered power supply 400, such as thevoltage converter 410, the voltage sensor 412, and or the current sensor414. The controller 408 may be or include a processing circuit such asan application specific integrated controller (ASIC), a fieldprogrammable gate array (FPGA), a programmed microprocessor, or otherapplicable controller types. In some embodiments, the controller 408 mayinclude a memory device, such as a random-access memory (RAM), read onlymemory (ROM), Flash memory, or another non-transitory computer readablemedium.

The voltage converter 410 is configured to convert a voltage of thebattery pack 102 (e.g. 18 VDC, 12 VDC) to a desired voltage level orlevels, such as 12 VDC, −12 VDC, 5 VDC, −5 VDC, 3.3 VDC, etc. As shownin FIG. 4 , the voltage converter 410 includes a low-power power supply(PS) 416 and a high-power power supply (PS) 418. Both the low-power PS416 and the high-power PS 418 are configured to output a desired voltagevia the output bus 420. In some embodiments, the low-power PS 416 and/orthe high-power PS 418 are coupled to the output bus 420 via a resistor.The output voltages of both the low-power PS 416 and the high-power PS418 are the same. In some examples, different voltages may be output bythe low-power PS 416 and the high-power PS 418 as well as commonvoltages. The low-power PS 416 is configured to output the desiredoutput voltage with a lower available amount of current (i.e. lowerpower output). For example, the low-power PS 416 may be configured tohave a maximum current output of 10 mA. However, output current valuesof more than 10 mA or less than 10 mA are also contemplated. Incontrast, the high-power PS 418 is configured to output the desiredoutput voltage with a higher available amount of current (i.e. a higherpower output). For example, the high-power PS 418 may be configured tohave a maximum current output of 500 mA. However, output current valuesof more than 500 mA or less than 500 mA are also contemplated.

The low-power PS 416 is configured to require a minimal operatingcurrent when no load is coupled to the output bus 420 of the powersupply 400. For example, the low-power PS 416 may be configured to drawless than 1 mA of current when there is no load connected to the powersupply 400. This reduced parasitic current draw reduces the discharge ofthe battery pack 406. Further, by maintaining a minimal amount of outputpower from the low-power PS 416, the high-power PS 418 may quickly beactivated when there is a load connected to the power supply 400requiring additional output power. Additionally, the low-power PS 416may provide power to the controller 408 when the battery pack 406 iscoupled to the power supply 400. In some embodiments, the controller 408may be configured to operate in a low power mode when the only thelow-power PS 416 is operating.

In some embodiments, the low-power PS 416 and high-power PS 418 arecontrolled by the controller 408 to provide an output via the output bus420. For example, the controller 408 may provide a signal to the voltageconverter 410 to activate either the low-power PS 416 or the high-powerPS 418 in response to one or more conditions being determined by thecontroller 408, such as those described in more detail below.

The voltage sensor 412 is configured to sense a voltage on the outputbus 420 representative of the output of the voltage converter 410. Thevoltage sensor 412 may further be configured to provide a signalrepresentative of the sensed voltage to the controller 408. The currentsensor 414 is configured to sense a current provided to a load via theoutput bus 420. The current sensor 414 may further be configured toprovide a signal representative of the sensed current to the controller408.

The power supply 400 may further include user input 422. The user input422 may be a switch or other user input to allow a user to selectivelycontrol the connection of the battery pack to the circuitry (i.e.voltage converter 410) of the power supply 400. In some embodiments, aninput may be provided to the controller 408 to power on the voltageconverter 410.

FIG. 5 is a flowchart illustrating a process 500 for controlling theoutput of a power supply. In some embodiments, the process 500 isperformed using the power supply 400 described above. At process block502, the controller 408 activates the low-power PS 416. In someembodiments, the controller 408 may activate the low-power PS 416 inresponse to receiving an indication that a battery pack has been coupledto the power supply 400. In other embodiments, the controller 408 mayactivate the low-power PS 416 in response to receiving a signal from theuser input 422. Activating the low-power PS 416 causes the low-power PSto provide an output via the output bus 420, as described above. Atprocess block 504, the controller 408 monitors an output voltageprovided to a load. In some embodiments, the voltage sensor 412 providesa signal representative of a voltage sensed on the output bus 420 to thecontroller 408.

At process block 506 the controller 408 determines if the output voltageis below a predetermined level. In some embodiments, the predeterminedlevel may a 20% reduction in voltage below the nominal voltage levelprovided to the output bus 420. For example, wherein the nominal outputvoltage of the voltage converter 410 is 12V, the predetermined level maybe 9.6V (12V-20%). However, predetermined levels or more than 20% orless than 20% are also contemplated. The drop in output voltage may bedue to a load being connected to the output bus 420 which requires morepower than is able to be provided by the low-power PS 416. Thus, thedrop in voltage is indicative of a load being connected to the outputbus 420. Due to the limited capacity of the low-power PS 416 to providethe required power, the voltage output from the low-power PS 416 willbegin to drop. In response to determining that the output voltage is notbelow the predetermined value, the controller 408 continues to monitorthe output voltage at process block 504.

In response to determining that the output voltage is below thepredetermined value at process block 506, the controller 408 deactivatesthe low-power PS 416 and activates the high-power PS 418 at processblock 508. While the above embodiment describes deactivating thelow-power PS 416 in response to an output voltage being below apredetermined threshold, other parameters, such as output power oroutput current, may also be used to deactivate the low-power PS 416. Theoutput power may be calculated by the controller 408 as a function ofthe output voltage and output current. For example, if the output poweris determined to exceed a predetermined threshold, the low-power PS 416may be deactivated by the controller 408. Examples of predeterminedvalues of increased power may be a 10% increase over a no-load powerdraw. However, increases of more than 10% or less than 10% are alsocontemplated. Other examples of predetermined values of power may be 120mW threshold. However, values of more than 120 mW or less than 120 mWare also contemplated. In other embodiments, an input power or currentmay also be monitored to determine a power draw of the power supply 400.For example, an increase in determined or sensed input power or currentcan indicate that the low-power PS 416 should be deactivated, and thehigh-power PS 418 be activated. For example, if the input current orpower exceeds a predetermined threshold, such as 10% of no-load currentor power, the controller 408 can deactivate the low-power PS 416 andactivate the high-power PS 418 at process block 508. Predeterminedthresholds of more than 10% or less than 10% are also contemplated.

In some embodiments, the low-power PS 416 provides power to thehigh-power PS 418 in response to a signal received from the controller408. In other embodiments, the controller 408 provides a signal to thevoltage converter 410, which then diverts output power from thelow-power PS 416 to the high-power PS 418 to turn on the high-power PS418 prior to deactivating the low-power PS 416. In further embodiments,the low-power PS 416 may provide power to control circuitry within thevoltage converter 410, thereby allowing the voltage converter 410 toactivate the high-power PS 418 and provide power from the battery packto the high-power PS 418. In some examples, the low-power PS 416 mayremain activated and the high-power PS 418 is also activated tosupplement the available output power.

At process block 510, the controller 408 monitors one or more outputcharacteristics of the output bus 420. In one embodiment, the controller408 monitors an output current of the voltage converter 410. In someembodiments, the current sensor 414 provides a signal representative ofthe current flowing to the load via the output bus 420 to the controller408. At process block 512, the controller 408 determines if the outputcurrent is below a predetermined value. In some embodiments, thepredetermined level is a current threshold value. For example, thepredetermined level may be 10 mA. However, predetermined levels of morethan 10 mA or less than 10 mA are also contemplated. In some examples,the predetermined levels may be equal to a maximum current output levelof the low-power PS 416. In other examples, the controller 408 maymonitor an output power at the output bus 420, as described above. Thecontroller 408 may determine whether the power is below a predeterminedthreshold, such as 10% of no-load power. In other examples, thepredetermined value may be a power value, such as 120 mW. However, powervalues of more than 120 mW or less than 120 mW are also contemplated.

The predetermined level is configured to represent a substantialreduction, or absence, of the load. Thus, the drop in current or powermay indicate a removal of the load from the output bus 420. In otherembodiments, the drop in current or power may indicate a reduced load,such as when an external device being charged via the output bus 420 isfully or nearly fully charged, requiring little or no current from thepower supply 400. In response to determining that the output current orpower is not below the predetermined value, the controller 408 continuesto monitor the output current at process block 510.

In response to determining that the output current or power is below thepredetermined value, the controller 408 deactivates the high-power PS418 and re-activates the low-power PS 416 to avoid unnecessary batterydischarge caused by powering the high-power PS 418. The controller 408then resumes monitoring the output voltage level at process block 504.

Thus, embodiments described herein provide, among other things,battery-powered power supplies that include a low-power power supply inaddition to a high-power power supply that can be automatically operatedbased on a sensed load. Various features and advantages are set forth inthe following claims.

What is claimed is:
 1. A method for controlling a battery-powered powersupply, the method comprising: supplying an output bus with a firstoutput from a first power supply within the battery-powered powersupply; monitoring a voltage of the first output; deactivating the firstpower supply in response to the monitored voltage being below a firstpredetermined threshold; and generating a second output from a secondpower supply within the battery-powered power supply, the second outputbeing configured to be coupled to the output bus.
 2. The method of claim1, further comprising: monitoring a current of the output bus;determining, via a controller of the battery-powered power supply,whether the current is less than a second predetermined threshold;deactivating the second power supply in response to determining that thecurrent is less than the second predetermined value; and reactivatingthe first power supply.
 3. The method of claim 1, further comprising:monitoring a current of an input to the battery-powered power supply;determining, via a controller of the battery-powered power supply,whether the current is less than a second predetermined value; anddeactivating the second power supply in response to determining that thecurrent is less than the second predetermined value; and reactivatingthe first power supply.
 4. The method of claim 1, wherein thebattery-powered power supply is powered by a rechargeable power toolbattery pack.
 5. The method of claim 1, wherein the first power supplyhas a no-load current draw of 1 mA or less.
 6. The method of claim 1,wherein the first power supply has a maximum output current of at least10 mA.
 7. The method of claim 1, wherein the second power supply has amaximum output current of at least 500 mA.
 8. A battery-powered powersupply comprising: a voltage converter including: a first power supply,and a second power supply, wherein the first power supply and the secondpower supply are configured to provide an output to a common output bus;a voltage sensor coupled to the output bus and configured to sense avoltage of the output bus; a current sensor configured to sense acurrent though the output bus; and a controller configured to: monitor avoltage of the output bus, and deactivate the first power supply andactivate the second power supply in response to determining that thevoltage of the output bus is less than a predetermined voltage level. 9.The power supply of claim 8, wherein the controller is furtherconfigured to: determine whether the current though the output bus isless than a predetermined current level; and deactivating the secondpower supply and activating the first power supply in response todetermining that the current is less than the predetermined currentlevel.
 10. The power supply of claim 9, wherein the predeterminedcurrent level is 10 mA.
 11. The power supply of claim 8, wherein thesecond power supply has a higher output power rating than the firstpower supply.
 12. The power supply of claim 8, wherein controller isfurther configured to monitor the voltage of the output bus during anactivation period of the first power supply.
 13. The power supply ofclaim 8, wherein the first power supply has a no-load current draw of 1mA or less.
 14. The power supply of claim 8, wherein the second powersupply has a maximum output current of at least 500 mA.
 15. A method forcontrolling a battery-powered power supply, the method comprising:generating a first output from a first power supply within thebattery-powered power supply, the first output being coupled to anoutput bus; monitoring a power output at the output bus; deactivatingthe first power supply in response to determining that the power outputat the output bus is less than a first predetermined level; andgenerating a second output from a second power supply within thebattery-powered power supply, the second output being coupled to theoutput bus.
 16. The method of claim 15, wherein the first predeterminedlevel is at least 120 mW.
 17. The method of claim 15, wherein the firstpower supply has a maximum output current of at least 500 mA.
 18. Themethod of claim 15, wherein the second power supply has a maximum outputcurrent of at least 10 mA.
 19. The method of claim 15, wherein thebattery-powered power supply is powered by a rechargeable power toolbattery pack.
 20. The method of claim 15, further comprising:determining, using a controller of the battery-powered power supply,whether the power output at the output bus is greater than the firstpredetermined level; deactivating the second power supply in response todetermining that the power output at the output bus is greater than thefirst predetermined level; and reactivating the first power supply.